The article provides a mathematical description based on the theory of differential equations, for the population dynamics of the parasite potato cyst nematodes (PCN). Parameters to the model are estimated from published data. We study different strategies to counter attack pest of PCN faced by potato producers. The relation between initial PCN density, annual multiplication rate and harvesting strategy is studied. Despite its simplicity we show that the model can provide realistic predictions. The dynamic model constitutes a powerful tool describing the mechanism or process by which the number of PCN can be studied and controlled. The mathematical framework can be used for studying other parasitic pests decreasing or inhibiting plant growth.